Instrument for blood grouping on blood grouping cards



Jan. 28, 1969 K. E. H. ELDON 3,424,553

INSTRUMENT FOR BLOOD GROUPING ON BLOOD GROUPING CARDS Filed Dec. 5, 1966Fig. 1

INVENTOR KNUD E. H. ELDON BY QL%,A;M4

ATTORNEYS United States Patent 6,317/ 65 U.S. Cl. 23253 5 Claims Int.Cl. G01n 33/16 ABSTRACT OF THE DISCLOSURE Apparatus for making bloodgrouping tests. Four bloodgrouping tests are made simultaneously,without danger of cross-contamination, by supporting drops of blood orother test liquid on four prongs extending from a common handle, andtransferring the drops to, and stirring the resulting test mixture at,separate test areas of a standard test card simultaneously bymanipulation of the handle. Optionally, a preliminary stirring step todissolve the dried test reagent in water is avoided by using a high saltconcentration in the dried reagent to cause the water to absorb, withoutstirring, suflicient salt to prevent adverse elfect onsubsequently-added blood samples.

Methods are known for carrying out blood grouping on blood groupingcards containing two or more testing areas, by which methods, with orwithout previous moistening of the area with water, a drop of the blood,which has to be examined, is supplied to every separate area, followedby a stirring. Instead of blood, a salt water suspension of bloodcorpuscles from the person, whose blood has to be examined, may be used.The cards may contain for example 2-5 testing areas, most frequently 4.Within each testing area the cards generally contain a dried drop oftest serum chosen for blood group test with an admixture of conglutininor congl-utinin substitute and salt.

The general method when using such a card for blood grouping withcapillary blood is as follows: at first one drop of plain water issupplied to each of the areas with a drop pipette. Then a stick of glassor plastic is used for stirring first one of the said drops of water,until the reagent contained therein is completely dissolved in thewater. The glass stick is then carefully wiped, and the same operationis repeated in one after the other of the further areas. Thereafter adrop of blood from the patient is taken up, for instance from the ear,on the point of the glass stick, and this drop is added to the dissolvedreagent in the first area and mixed with it.

The glass stick is cleaned, and the operation repeated with the otherareas. A suitable, prescribed time, which may be for instance 1 minute,after the operation has been carried out as regards the last area, thecard is rocked to a completely vertical position in differentdirections, and other rocking for instance for 2 minutes, the areas ofthe card are examined and the reaction noted.

This method is on many points unfavourablly troublesome and timedemanding, especially when it has to be done ambulant, for instance onthe scene of an accident, or beside a stretcher, where the essentialpurpose is to have a blood transfusion established as quickly aspossible. Thus the separate treatment with water of the reagent contentsof the testing areas, with the wiping if the glass stick inbetween,takes a considerable time and the same goes for the separate mixing andspreading of the testing blood within the areas. Further the 3,424,558Patented Jan. 28, 1969 method involves danger of false reactions, ifserum is transferred from one section to another.

The invention concerns a method, by which these disadvantages areremoved or considerably reduced.

According to the invention the procedure for this purpose is that theblood is supplied by placing a drop of the patients blood on each of anumber of blood transferring surfaces, which with respect to the number,mutual distance and mutual position thereof correspond to the testingareas of the card, said transferring surfaces being present on thefurcations of a furcated instrument, which thereafter is used totransfer the blood samples to the test areas and to effect thesubsequent stirring and distributing operations in a plurality of thesaid areas at one time.

Hereby the purpose aimed at is obtained, as the in dividual mixingoperations are carried out at one time in a plurality, maybe all of theareas, whereby time consumption is considerably reduced. Moreover falsereaction is avoided, as every prong of the instrument contacts only oneof the areas, which applies also in the case, where two mixingoperations are required, one with water and a following one with blood.Preferably, however, in the latter case two separate instruments aremade use of, one for each of the operations, discarding the firstinstrument before using the other one.

The method may, however, also be carried out so that only one mixingoperation is undertaken, viz. in connection with the placing of thepatients blood in the areas. In that case, the water is supplied to theareas in advance without carrying out the operation of stirring thewater in order to dissolve the reagent; when carrying out thisembodiment of the invention, the distribution of the water does not takeplace, until the blood sample has been added. This can only be done,when the composition of the serum portions used in the production of thecards for covering each test area has been adjusted to suit this method;on the other hand, the composition required is within limits known perse. Thus the adaption for this embodiment of the method according to theinvention may be obtained by altering the salt concentration in theserum portions to be somewhat higher than usual. The specificity of thesamples is not affected by the change in composition necessary forobtaining this purpose. When these precautions have been taken at thepreparation of the card, a water drop added without stirring is capableof absorbing sufficient salt to prevent the occurrence ofagglutinationlike or agglutination restraining or hemolysing (bloodcorpuscle dissolving) phenomena, when the blood is brought in contacttherewith.

In this case, blood grouping can be carried out particularly fast, asthe introductory water mixing operation is done away with.

The invention further concerns an [instrument for carrying out themethod described above, which instrument is characterized in that it hasthe shape of a comb, the teeth of which have a flat area for thepicking-up of a blood drop. As the teeth are elaborated so that the saidareas have mutual distances corresponding to the test areas, it is thuspossible at one time to transfer blood to all test areas, just byeplacing the teeth of the comb so that the blood gets into contact withthe areas or with a drop of water placed on each of them.

According to a particularly advantageous embodiment of the instrument,the flat areas are formed as the end surfaces on the prongs, and theprongs have a bent shape for the creation of short outer sections, whichare all in the same plane and create such an angle with the plane of thecomb that the outer sections at the same time conveniently can be placedagainst each of the blood grouping areas. Hereby it is obtained that thewater 3 and the blood from the end surfaces can simultaneously be mixedand distributed over all test areas.

The instrument is preferably manufactured from plastic, thereby usingespecially a plastic type, which has a good adhesion towards water.

To illustrate the method and the instrument, the drawing shows:

FIG. 1, an example for the execution on a testing card,

FIG. 2, instrument according to the invention, seen from the side, and,

FIG. 3, same in section.

In FIG. 1, 1 is a card, which, as shown, may contain an area 2 forstatement of the data of the patient, such as name, address, age etcetera, and an area 3, in which to sum up the results of the groupingtest. 4-7 are test areas, each of which contains a dried drop of testserum. Area 4 may thus contain a test serum, wherein the specificingredient is anti-A serum, area 5 is a similar drop containing anti-Bserum, the area 6 contains anti-D serum, and the area 7 a drop, whichcontains only an unspecific serum, and which serves as a control toreveal, whether circumstances are present, which can make the reactionsobtained in the other areas unvalid, for instance in consequence of thepatients blood being panagglutinative.

As mentioned by way of introduction it is known that serum in thegrouping areas contains conglutinin or conglutinin substitute and salt.Blood grouping cards, where 60 mml. reagent consisting of 6 mml. serumand 54 mml. 6% dexstrane solution with 0.9% NaCl are dried in each testarea, are thus known. If the amount of salts contained in the saidquantity of serum is converted into the equivalent quantity of NaCl, thesalt concentration in the serum will also be 0.9%, and the salt contentsin each reagent dose will correspond to 0.540 mg. NaCl, of which 0.480mg. originates in the dexstrane solution, whereas 0.060 mg. equals tothe serum salts. When the cards are to be used in connection with thepresent method, the quantity of salt ought to be larger. Experimentshave shown that the amount of salt is advantageously increased inportion to the usual salt quantity mentioned above, by an extra quantityof about 0.175 mg. NaCl calculated on 60 mml. reagent of the abovementioned composition. Hereby the solution of the reagent dried in thetest areas is promoted and a quicker raise of the salt concentration inthe measured drop of water is obtained, whereby also the reactionstrength of the agglutinations is increased.

In FIGS. 2 and 3 is shown an embodiment of the instnurnent used incarrying out the method described above and so shaped that itcorresponds to the card shown in FIG. 1. The instrument consists of aholding plate 8, from which four teeth 9 are extending, each having aplane end surface 10 and a bent outer section 11. The distance betweenthe prongs, and thereby between the outer sections 11, corresponds tothe distance between the areas 4-7 mutually. The use of the instrumentis described above.

What I claim is:

1. An instrument for simultaneously transferring a plurality of separatedrops of test liquid respectively to a plurality of linearly spaced testareas on a blood-grouping test card or the like, comprising acomb-shaped body having a handle and a plurality of spaced pron-gsextending therefrom, said prongs each having a closed flat face ofpredetermined area for carrying a drop of liquid and such prongs beingspaced and positioned to disposed said liquid-carrying faces in positionto be engaged simultaneously with the spaced test areas on the card.

2. An instrument as set forth in claim 1, wherein the prongs have mainportions which lie in a common plane and short bent end sections whichlie in a common plane at an angle to the plane of the main portions suchthat the end sections can be placed simultaneously against the testareas, and the liquid-carrying faces are formed as fiat end faces on theend sections.

3. In combination, apparatus for simultaneously carrying out a pluralityof blood grouping tests, comprising a test card having a plurality oflinearly-spaced coplanar test areas each carrying the dried residue of atest serum and conglutinen or conglutinen substitute together with saltsin a concentration of least equal to the osmotic equivalent of 0.9percent sodium chloride, such residue being adapted to dissolve into adrop of water deposited on the test area and admixed with the residue,each moistened test area being adapted to undergo a test reaction with adrop of blood subsequently placed thereon, and an instrument as definedin claim 1, in which the liquid-carrying flat faces are spaced to beengaged with the spaced test areas on the card.

4. A combination as set forth in claim 3, wherein the dried residues onthe test areas of the card contain salts in a concentration exceedingthe osmotic equivalent of 0.9 percent sodium chloride, the salt contentbeing such that without stirring the water dissolves sulficient salt toprevent the occurrence of adverse reactions when the blood issubsequently added 5. A combination as set forth in claim 4 in which theinstrument prongs have main portions and short bent end sections whichlie in a common plane at an angle to the main portions such that the endsections can be simultaneously placed fiatwise against the test areas,the liquid carrying faces being formed as end faces on the end sections.

References Cited UNITED STATES PATENTS 2,770,572 11/1956 Eldon 16784.53,276,847 10/1966 Duff et al. 23292 FOREIGN PATENTS 393,009 10/1908France. 1,032,410 3/ 1953 France.

82,305 1/ 1895 Germany. 14,874 6/ 1902 England.

MORRIS O. WOLK, Primary Examiner.

ELLIOTT A. KATZ, Assistant Examiner.

U.S. Cl. X.R: 23230; 222-420 PO40) UNITED STATES PATENT OFFICECERTIFICATE OF CORRECTION Patent No. 3,424,558 Dated January 28, 1969Inventor(s) K. E. H. Eldon It is certified that error appears in theabove-identified patent and that said Letters Patent are herebycorrected as shown below:

Column 1, line 60, "other" should read after line 70, "if" should readof Column 2, line 62, "bye" should read by Column 4, line 6, "disposed"should read dispose SIGNED AND SEALED AUG 2 6 1959 saw my WILLIAM E.SOZ'IU'ZLER, JR. 1' 5 wfldcri Conmlissioucr oi Patents

